1. Field of the Invention
The present invention relates to a photosensitive material drying apparatus and, more particularly, to a photosensitive material drying apparatus for drying a photosensitive material by blowing warm air onto it.
2. Description of the Related Art
A conventionally known photosensitive material drying apparatus for drying a photosensitive material such as photographic film by blowing warm air onto the same is arranged as follows. A vertically extending transport passage for a film is formed by a plurality of rollers in a photosensitive material drying apparatus, and the plurality of rollers are arranged at equal intervals in a zigzag manner. The film which has been developed by wet process and which is in a wet condition is introduced into the drying apparatus, and transported while being guided by the rollers along the transport passage therein. A plurality of warm-air supplying chambers are disposed in the vicinity of the rollers in two rows with the film transport passage placed therebetween. Warm air produced by a fan and a heater is supplied to the warm-air supplying chambers. Each warm-air supplying chamber is provided with two warm-air discharge ports along the traveling direction of the film. The warm air supplied to each warm-air supplying chamber is discharged through the warm-air discharge ports onto the film portions each located in the vicinity and upstream, as viewed in the traveling direction of the film, of a respective roller-contacting portion of the film. The film is thus dried.
To reduce the drying time in the apparatus for drying film by blowing warm air onto it, the amount of warm air blown onto the film is usually increased since increasing the temperature of the warm air can disadvantageously cause the film to curl. With respect to the above-described conventional photosensitive material drying apparatus, however, if the distance between the warm-air discharge port and the film is reduced to increase the amount of warm air blown and the warm air is blown onto the film perpendicularly thereto, the drying efficiency with respect to each film portion located in proximity to the roller-contacting portion of the film becomes aggravated, resulting in unevenness in drying.
To overcome this problem, a photosensitive material drying apparatus has been proposed in which, as shown in FIG. 17, warm air is discharged diagonally toward film portions each located in proximity to the respective roller-contacting portion of a film 774 through pairs of warm-air discharge ports 778 respectively provided on the upstream and downstream sides with a respective roller 772 placed therebetween along the film transport passage (Japanese Patent Application Laid-Open No. 1-123236).
With this photosensitive material drying apparatus, as warm air is discharged diagonally toward each film portion located in proximity to and upstream of the respective roller-contacting portion of the film 774 (in the direction of arrow E in FIG. 17) and toward each film portion located in proximity to and downstream of that roller-contacting portion of the film 774 (in the direction of arrow F in FIG. 17), water remaining in proximity to each roller-contacting portion of the film 774 is caused to evaporate so as to eliminate unevenness in the drying of the film 774. In addition, the warm air discharged through the warm-air discharge ports 778, after evaporating the water on the film 774 and becoming highly humid, is allowed to escape in a direction away from the film 774 through exhaust holes 779 each formed in a respective warm-air supplying chamber 776 in such a manner as to extend transversely therethrough between extensions of the pair of warm-air discharge ports 778.
However, with the conventional photosensitive material drying apparatus mentioned first and the photosensitive material drying apparatus disclosed in the aforementioned Japanese Patent Application Laid-Open No. 1-123236, the warm air is discharged toward the film through the pairs of warm-air discharge ports provided in the warm-air supplying chambers, and the warm air thus discharged is mainly exhausted between the respective pairs of warm-air discharge ports through the exhaust holes formed in the respective warm-air supplying chambers. Hence, there are cases where the exhausting of air after drying lags behind, with the result that the highly humid air remains in the vicinity of the film. For this reason, there has been a drawback in that the efficiency with which the film is dried is deteriorated.
In addition, in a case where variations occur in the traveling speed of the film owing to contact between each roller and the tip of the film being transported by the rollers, the following problem can occur. With the photosensitive material drying apparatus in which warm air is constantly blown onto film portions each located in the vicinity and upstream of the roller-contacting portion of the film, since the warm-air discharge ports are arranged at equal intervals, the warm air fails to be blown evenly with respect to the traveling direction. Hence, there occur in the film those portions onto which a greater amount of warm air is blown as compared with the remaining portions, resulting in unevenness in the drying of the film.